Printing system with file specification parsing capability

Abstract: A printing system (25), for producing prints from a print file designated by a print file specification expressed in a first format, is provided. The printing system (35) includes a workstation (14) and a print server (25) for storing the print file. An operating system, employing a second format, cooperates with the workstation (14) and the print server (25) to permit communication between the workstation (14) and the print server (25). A parsing arrangement converts the first format of the print file specification to an output string based on the second format when a call to output the stored print file is transmitted from the workstation (14) to the print server (25).

Description: The present invention relates generally to a technique for a printing system with an operating system and, more particularly, to an apparatus and method which permits a print service application to perform input/output operations on files whose formats necessarily differ from that of the operating system of the printing system. Xerox® Corporation presently is marketing a server for a printing apparatus, the server being referred to as the DocuTech® Network Server ("DocuTech Network Server" is a trademark of Xerox Corp.) This server is adapted to translate a job written in a first PDL (Page Description Language), such as PS (PostScript) or HP-PCL (Hewlett Packard Printer Control Language), into a second PDL, such as Interpress, for printing of the job on a Xerox® compatible printing apparatus. At the heart of the server are two interpreters, one of which is adapted to translate PS and the other of which is adapted to translate PCL. Each interpreter contains software, written by either Adobe® Systems Inc. or Peerless® Corp. to facilitate the translation process. Additionally, Eastman Kodak produces a network printing system, known as "LionHeart™", which employs a print server. The above-mentioned DocuTech™ Network Server couples one or more workstations with a print server by way of a network operating system, such as Netware®. The print server preferably employs a print service software application which recognizes files having paths or file specifications written in a DOS™ format. It has been found, however, that the print service software application does not recognize non-DOS™ file specifications unless they are expressed in DOS™ format. It would be desirable to provide a print server, with a print service application hich is adapted to recognize files that derive from both DOS™ and non-DOS™ based workstations. Accordingly, the present invention provides a printing system for producing prints from a print file designated by a print file specification expressed in a first format, including: a workstation; a print server for storing the print file; an operating system employing a second format, the operating system cooperating with the workstation and the print server to permit communication between the workstation and the print server; and means for converting the first format of the print file specification to an output string based on the second format when a call to output the stored print file is transmitted from the workstation to the print server. In one embodiment the converting means resides in the print server, and in another embodiment the printer server is integrated with the printer Additionally, there is provided a method of producing prints in a printing system with a selected print file designated by a file specification expressed in a first format, the printing system including a workstation and a print server capable of storing files, the workstation and the print server communicating with one another through an operating system employing a second format, including the steps of: storing the selected print file to the print server; transmitting a signal from the workstation to the print server calling for the output of the stored print file, the signal including the file specification; converting the first format of the file specification to the second format of the operating system for placing the print file in an outputable form. The present invention will be described further by way of examples, with reference to the accompanying drawings, in which:- Figure 1 is a schematic view of a printing system including a plurality of client workstations interfaced with a printer by a print server; Figure 2 is a schematic view of a job file and the contents thereof; Figure 3 is a representation of a format for an electronic job ticket; Figure 4 is a schematic, block diagrammatic view of the printer and the print server; Figure 5 is a schematic view of a memory map capable of being used to interpret a page description language ("PDL"), i. e. a sequence of instructions employed to translate PDL contained in the job file; Figure 6 is a partial, block diagrammatic view of the printing system of Figure 1; Figure 7 is a flow diagram depicting a preferred procedure for setting up a print job request; Figure 8 is a block diagram illustrating a preferred approach for parsing a file specification to form an output string; and Figures 9-10 conjunctively represent a flow diagram depicting a preferred procedure for parsing a file specification to form an output string. Referring to Figure 1, there is shown a printing arrangement, designated generally by the numeral 10. The printing arrangement 10 includes a plurality of remote inputs such as PCs, workstations, etc. (referred to herein as workstations 14), coupled via one or more networks 20 to a server 25. Workstations 14 include a CRT type display screen 15 together with keyboard and mouse for entering programming instructions, image data, etc. Screen 15, which may be a touchscreen, displays various job program choices, operator instructions, messages, etc. The server 25 is, in turn, coupled through one or more networks 28 to one or more printing systems 35. While separate networks 20, 28 are shown, a single network may instead be used. Referring to Figure 2, electronic job files 60, or parts thereof, are created at the individual workstations 14, each job file being comprised of a Job Specification 62 and Print Data file 63 expressed in a PDL. Job Specification 62 is in the form of a client server job ticket 64 having instructions for routing, handling, and processing the job 62. As will be clarified from the discussion below, in the preferred embodiment of the present invention, the PDL of print data file 63 is either written in Postscript® ("PS") or Hewlett Packard Printer Control Language ("HP-PCL"). The jobs in Print Data file 63 are electronic in form, consisting of image signals or pixels generated, for example, by scanning hard copy documents and converting the document images to image signals or pixels, directly by a keyboard, taken from memory, or consisting of page format and/or graphic output commands all encoded in one of the preferred PDL encodings. The content of the job files are normally compressed to increase bandwidth and reduce the amount of storage required. The image signals, pixels or PDL instructions in Print Data File 63 are arranged as electronic documents or pages for printing on a print media such as paper stock or sheets. The programming instructions in the client server job ticket 64 accompanying the job file 60 may include selection of the printer in the case where plural printers are available for the client or user to choose from in printing system 35. Where a printing system 35 has printers with different features, functions, speeds, etc., it may be necessary that the client select the printer that is to be used initially so that a client server job ticket 64 with the program selections available with that printer may be displayed at the client's workstation 14 as described more fully in Europan Application No. 92 306 944.7. During the printing process, the server 25 transmits the printing instructions from the client server job ticket 64 to the printing system selected. Referring to Figure 3, the client server job ticket 64 may assume an ASCII format. Additionally, by employment of suitable client UI interface dialog software, print job selections may be displayed on the display screen 15 so that the user can be apprised of which printing selections are available for programming a print job. Examples of client server job ticket displays are shown in US-A-5,226,112. The client at the workstation interactively fills out the client server job ticket by making selections electronically using the workstation mouse, keyboard, etc. It should be recognized that the client server job ticket instructions encompass not only print programming instructions for the job itself but also routing and handling instructions for the server 25. The completed client server job ticket 64 is combined with the job in Print Data file 63 in the job file 60. The client server job ticket includes information regarding a print file specification for the job file 60. In the illustrated embodiment of Figure 3, the print file specification is designated with the parameters: "%XRXsourceFile" and "%XRXdestination". The significance of the print file specification to the present description will be discussed in further detail below. The server 25 comprises any suitable interface for receiving job files 60 from workstations via network 20, with the ability to access and decode the job processing instructions on the accompanying client server job ticket. The server 25 preferably includes an on-board memory of suitable capacity for temporarily storing the job files pending processing thereof by printing system 35. The print manager on-board memory may be large enough to support long term storage of the job files or parts of the job files Alternately, one or more remote memories 42 (Figure 1) may be provided for this purpose. The printing system 35 may include one or more high speed electronic printers 50 for processing jobs in accordance with the instructions input through the client server job ticket accompanying each job file While a single printer 50 is shown, plural printers, either at a single central location or at several remote locations may be envisioned Printer 50, for example, may be a xerographic based printer of the type snown and described in US-A-S,170,340. In other contemplated implementations of the preferred embodiment, the printer 50 could comprise other known printer types such as ink jet, ionographic, LED, and the like. Referring to Figure 4, the structure of the server 25 and the printing system 35 is discussed in further detail In the preferred embodiment of the invention, a swapping technique is achieved with an arrangement that is designated by the numeral 70. The software used to operate the arrangement 70 is hereinafter referred to as the "print service application". The arrangement includes a host processor 72, an accelerator coprocessor (ACP) card 74 and a disk storage device 76. In one example, the host processor is an IBM PC-AT system having an Industry Standard Architecture (ISA) or an Extended Industry Standard Architecture (EISA) bus to accept the ACP card. The host processor 72 can be configured for operation in a network environment. When the host processor 72 is configured for network operation, it is preferably Novell® certified for Netware 386™. In the preferred embodiment, the ACP card 74 comprises the following major blocks: 80960CA Microprocessor Host System ISA Interface Extended Bus Interface Memory (16 MBytes) Programmable Read Only Memory Timer/Counter 256 Byte Board Identification EEPROM The host processor 72 is capable of transferring data to and from ACP memory through a 128K byte sliding shared memory window The ACP 74 also can use a small section of the host processor's IO address space. By writing to an IO data port of the ACP 74, the host processor 72 is able to send commands to the ACP 74. In turn, by reading the IO data port, the host processor 72 is able to receive acknowledgement messages back from the ACP 74 These messages are typically 1 byte in length and are used to synchronize the actual data transfers in shared memory In the preferred embodiment, two 8 bit data ports are used to communicate synchronizing swap requests and acknowledgements between the ACP 74 and the host processor 72 prior to the actual transfer of PDL decomposer code and font cache data. These two ports are referred to as: the Host to Processor and Processor to Host Data Registers ("HPDR" and "PHDR"). Referring still to Figure 4, the ACP card 74 is shown with a memory map 78-1, which memory map 78-1 includes all of the software necessary to interpret a page description language, and the 80960CA microprocessor, the microprocessor being designated by the numeral 80. Referring to Figure 5, the memory map 78-1, which includes a user section 82 and a system section 84, is shown in greater detail. The memory map 78-1 further includes a section 86 having registers through which the HPDR and the PHDR can communicate and a status flag can be set. In the illustrated embodiment of Figure 5, the user section 82 comprises a section for retaining PDL interpretation code, the PDL interpretation code being adapted to facilitate the interpretation of a job file expressed in a first PDL, such as PS or HP-PCL. In the preferred embodiment, the PDL interpretation code is written by either Adobe® Systems Inc. or Peerless®. Corp., in conjunction with Xerox® Corp., for use by Xerox® Corp. in its Xerox Production Print Services System ("Xerox Production Print Services" is a trademark of Xerox® Corp.), the Xerox Production Print Services System preferably including a Media Server and a Network Server. It should be understood that the PDL interpretation code facilitates translation of the job file 60 from a first PDL, such as PS or HP-PCL, into a second PDL file, such as Interpress. Those skilled in the art will appreciate that such translation could be, in one example, achieved by using a configurable PDL interpreter, such as one manufactured by Adobe® Systems Inc. or Peerless® Corp to reduce the text and graphics of the job file 60 into a bitmap and then to express the bitmap in the form of a second PDL, such as Interpress. It should be appreciated that only selected portions of the system section 84 are shown. Much of the software for the section 84 simply serves as one of various approaches for implementing the processes illustrated in Figures 6 and 7A-7B, the significance of which processes will be discussed in further detail below. It will be recognized by those skilled in the art that, in practice, various software tools, such as tables, e.g., fault, system procedure and control tables, timers and controls therefore, control implementations, storage locations, and stacks, typically would be employed in the implementation of the system section 84. Referring to Figures 4 and 5, the microprocessor 80 includes a section 90 which contains information regarding the internal state of the microprocessor 80, such information including 1K memory, registers and states. This information selectively can be stored in a layer 92 of the system section 84. Referring specifically to Figure 4, the host processor 72 is coupled with the disk drive device 76 so that, as explained in further detail below, portions of the memory map 78-1 can be transferred, in the form of a context file, thereto. Preferably, at any one moment, one or more PDL context files, designated by the numeral 94, are stored in the disk drive 76. Upon processing a job file 60, the interpreted PDL file can be transmitted to one of a plurality of output or printing devices. In the preferred embodiment, the interpreted PDL file is expressed in Interpress, and is transmitted to the printer 50 which comprises a decomposer 96 and an image output terminal (IOT) 98. In one example, the decomposer 96 is of the type used in a Xerox® 4045 ("Xerox 4045" is a trademark used by Xerox®) printer and employs software of the type described in Interpress: The Source Book. Additionally, the IOT can be any suitable print engine, such as the DocuTech™ print engine mentioned above. In operating the printer, the interpreted output from the host processor 72 is transmitted to the decomposer 96 where it is decomposed into graphics and text for printing by the IOT 98. Further details regarding the swapping technique implemented with the arrangement 70 is discussed in US-A-5,226,112. Referring to Figure 6 a known simplified network printing arrangement is shown in which one of the clients 14 (Figure 1), using a first format to represent jobs, such as a DOS format, communicates with the printer 35 by way of a network operating system, such as Netware ("Netware" is a registered trademark of Novell, Inc.) which network operating system also uses the first format. While this simplified arrangement is well suited for many network printing situations, it is not well suited for handling the type of situation illustrated by Figure 6 in which the client 14 uses a second format, which differs from the first format, and the workstation is coupled with the printer by way of a print server, the print server including the arrangement 70 (Figure 4) and print service application software (not shown). In one example, a job file ("file") is stored out to the disk 76 of arrangement 70 and a print request for the file is transmitted to the print service application (Figure 4) from the client 14 (Figure 1). For ease of discussion, the arrangements of Figures 1 and 4 are shown by Figure 6 in a simplified form. In the illustrated embodiment of Figure 6, a network operating system is shown as a single box, but in common practice, the network operating system would be integrated with the client 14 and the print service application. Moreover, it will be appreciated that the disclosed technique could be employed with other applications without affecting the concept upon which the disclosed technique is based. In operation of the printing arrangement 10, the client 14 requests or calls a file by way of its file specification, the file specification including information regarding where the file is stored on the disk 76 (designated as "Volume Name" in Figures 8-10), the directory(s) which must be accessed in order to find the file and the name of the file. If the client uses a file specification format which is the same as the network operating system, (Figure 6) the file can be processed in accordance with the request. If on the other hand, the file specification format differs from that of the network operating system format, as is the case for the illustrated embodiment of Figure 6, then the print service application fails to recognize the file in the disk 76 and returns a fault message to the client. To aid the print service in recognizing the file whose format is different than that of the print service application, a file specification parser 200 is preferably included in the arrangement of Figure 6. Referring to Figures 7-10, the operation of the file specification parser 200 is explained in further detail. Generally, Figure 7 is directed toward setting up a print job request and Figures 8-10 are directed toward a preferred parsing routine. Referring specifically to Figure 7, one of the clients 14 (Figure 6) submits a print request (step 202) and the print server assumes, at step 204, the rights of that client. In one example, the network operating system employs Netware®,a system with a DOS™ format. Accordingly, if the client is DOS™ based, the parsing process is unnecessary (step 206). When the client uses a non-DOS™ based format, however, the default volume of the disk 76 is changed, at step 208, to be one that has a name space loaded on it corresponding with the print request. Referring again to Figure 3, the name space derives from the file specification information of the job ticket. In one example, the name space relates to either a MAC or SUN operating system ("MAC" and "SUN" are respective trademarks of Apple Computers and Sun Systems). It will be appreciated by those skilled in the art that the concept of the preferred parsing technique can be applied with formats other than those used with MAC and SUN operating systems. Upon setting the current name space to the requested name space (step 210) the parser checks for errors (step 212). If an error exists due to, for example, the volume not having the name space, server rights are restored at step 214 and a fault message is issued. If no error is found at step 212, a suitable file specification parsing function, i. e., file specification parsing function is registered at step 216. If any error arises at step 218, the name space is set to DOS™ format (step 220) and server rights are restored at step 214: otherwise a success indication is issued at step 222. Referring to Figure 8, the basic principle underlying the operation of the parser 200 is shown. Essentially, the file specification, which is divided into a plurality of pieces that are respectively expressed by the terms "volume name", "directories" and "file name", is communicated to the parser 200 where the file specification is processed in accordance with the preferred method of Figures 9 and 10. As a result of the processing, an "output string", having a format compatible with the network operating system format, is generated. Referring to Figures 9-10, the operation of the parser 200 is discussed in further detail. A file specification is inputted to the parser and, upon setting environmental default values (step 224), the length of the file specification, which varies as a function of the length of the names and directories (Figure 8), is stored (step 226). During steps 228, 230 and 232, the file specification is prepared for parsing. In particular, the length of the file specification is calculated. The amount of memory required for the calculated length is allocated, at step 234 and an error check is performed at step 236. If there is an error, i. e., there is not enough memory, then the process reports an "OUT OF MEMORY CONDITION" (step 237) and returns from the parsing method; otherwise, per steps 238, 240 and 242, the process fetches a piece of the file specification which precedes a file specification separator. More specifically a volume name for the file specification is retrieved. At step 246, the process gets a volume number which corresponds to the retrieved volume name and, at step 248 checks for any errors. If there is an error, the memory allocated at step 234 is freed up (step 250), a bad volume name is reported (step 252) and the process is returned (step 254). Assuming no error is found at step 248, another piece of the file specification is obtained (step 256), and the output string is generated with the steps 258, 260, 262, 264 and 266. It should be appreciated that the output string is constructed to correspond with the format of the network operating system. In one example, the file specification format is parsed from either a MAC or SUN format into a Novell® Netware® format. As mentioned above the concept of the presently described parsing method is applicable to formats other than those of MAC, SUN and Novell®. It can be recognized that step 258 serves to check when the parsing method is complete. That is after each piece of the file specification has been used to construct the output string, the process is diverted to steps 268, 270 and 254 where, among other steps the memory allocated in step 234 is freed up and success is reported. After the parsing method is complete the environment of the print service is restored. That is, the default volume is changed to be one that has a name space loaded on it corresponding with the format of the network operating system, and server rights are restored. Numerous features of the present invention will be appreciated by those skilled in the art. One feature of the disclosed embodiment is that convenience is maximized for users of a network printing system with multiple client (workstation) types. That is, each user can designate his/her print file with a file specification that corresponds with his/her platform without any concern as to the format of the network operating system. Another feature of the disclosed embodiment is that the manner in which the user's file specification is handled by the printing system is transparent to the user. This sort of transparency enhances the marketability of the disclosed printing system since it facilitates the user's capability to obtain demand reprint across a large variety of native platform environments.

Claims: A printing system (35) for producing prints from a print file (63) designated by a print file specification (62) expressed in a first format, said print file specification including information regarding where the file is stored, the directory(s) which must be accessed in order to find the file, and the name of the file, including a workstation (14); and a print server (25), characterized in that said print server (25) is adapted for storing the print file; and that it further includes an operating system employing a second format, said operating system cooperating with said workstation (14) and said print server (25) to permit communication between said workstation and said print server; and converting means for converting the first format of the print file specification to an output string based on the second format when a call to output the stored print file is transmitted from said workstation (14) to said print server (25). A printing system as claimed in claim 1, further comprising a printer (50), wherein the call to output the stored print file includes a call to print the print file at said printer. A printing system as claimed in claim 1 or claim 2, in which the print file (63) includes a first page description language, further comprising a page description language interpreter for translating the first page description of the print file into a second page description language. A printing system as claimed in claim 3, further comprising a decomposer (96) for decomposing the second page description language of the print file to place the print file in a printable form. A printing system as claimed in any one of claims 1 to 4, in which prints are produced from a second print file designated by a second print file specification expressed in a third format, and the second print file is stored in said print server, wherein the third format of the second file specification is converted to a second output string expressed in the second format when a second call to print the stored second print file is transmitted from said workstation to said print server. A printing system as claimed in claim 5, in which the printing system includes a second workstation communicating with said print server, wherein the first call is transmitted by said first workstation and the second call is transmitted by said second workstation. A printing system as claimed in any one of claims 1 to 6, wherein the first print file is generated at said workstation and transmitted to said print server. A method of producing prints in a printing system (35) with a selected print file (63) designated by a file specification (62) expressed in a first format, said file specification including information regarding where the file is stored, the directory(s) which must be accessed in order to find the file, and the name of the file, the printing system (35) including a workstation (14) and a print server (25) capable of storing files, the workstation (14) and the print server (25) communicating with one another through an operating system employing a second format, characterized by storing the selected print file to the print server (25); transmitting a signal from the workstation (14) to the print server (25) calling for the output of the stored print file, the signal including the file specification; converting the first format of the file specification to the second format of the operating system for placing the print file in an outputable form. A method as claimed in claim 8, in which the file specification includes a plurality of pieces, with each piece having a length, further comprising determining the length of one of the pieces; and generating a portion of the output string with the determined length. A method as ciaimed in claim 9, in which memory space is allocated in the print server to form the output string, and the allocated memory space is divided into a plurality of portions including a first portion and a second portion, wherein said generating step comprises: storing the determined length of the one piece in the first portion of the output string; and copying the one piece from the file specification to the second portion of the output string.

Inventors: FURMAN LISA D, FURMAN, LISA D.
Applicants: XEROX CORP, XEROX CORPORATION
Application year: 1994
Main classification: G06F3
IPC codes: B41J5, G06F3